1. Field of the Invention
The present invention relates to an image-based container defects detector, and more particularly, to an image based container detector applicable in a container yard, or an inspecting station to detect the position and size of the container defect in the crucial time. If it is in combined use with the container number recognizer, it can improve efficiency and capacity of freight handling and contribute to automation of freight handling in the container yard.
2. Description of the Prior Art
Up to now, the way for finding out container defects is inspecting the container outer appearance by visual observation to record the defected positions and their sizes on the paper. But in this manual approach it is unable to find out defects in crutial time. It also causes potential danger and wasting time and manpower for the worker to work by foot for inspecting containers one by one.
In general, the procedure for conventional image-based container defects detector is at first to prepare the original container image, and then to find out the defects by subtracting the backround image from the newly captured image. Should the difference be exceeding a prescribed value, it is judged abnormal. Since the distance from the CCD camera to the container in the captured image is not equal to that in the original background image, or by extra interference arising from the container's dirts or background noise, the aforementioned difference will be too large to obtain an allowable recognition precisement.
Meanwhile, being affected by light sources, the color rendering of the dark background image obtained thereof will not be appreciable.
In view of the foregoing situation, the inventors of the invention herein conducted intensive research based on many years of experience gained through professional engagement in this field, with continuous experimentation and improvement culminating in the development of this dexterous image-based container defects detector.